Targeted therapy drugs interfere with the way cancer cells signal or interact with each other. This stops them growing and dividing.
For secondary breast cancer you usually have targeted therapy drugs with chemotherapy or hormonal therapy drugs. Your doctor will explain which targeted therapy drug or drugs are suitable for you. This depends on whether the cancer cells have receptors for the HER2 protein or for the hormone oestrogen. We have more about receptors in our information about secondary breast cancer.
Trastuzumab is the main targeted therapy drug used to treat HER2 positive secondary breast cancer. It was previously called Herceptin®.
Trastuzumab can be given:
- with another targeted therapy drug called pertuzumab (Perjeta®) and a chemotherapy drug, such as docetaxel (Taxotere®) We have more information about pertuzumab, trastuzumab and docetaxel given together.
- with chemotherapy drugs, such as paclitaxel (Taxol®), docetaxel, vinorelbine (Navelbine®) or capecitabine (Xeloda®).
You will have trastuzumab in one of the following ways:
- As a drip (infusion) into a vein every 3 weeks
- As a small injection under the skin.
Pertuzumab (Perjeta®) is another targeted therapy drug that works in a similar way to trastuzumab. It is usually given with trastuzumab and the chemotherapy drug docetaxel. If you have not had a targeted therapy drug or chemotherapy before, you may have this as your first treatment.
You will have pertuzumab into a vein (intravenously) as a drip (infusion) every 3 weeks.
We have more information about pertuzumab, trastuzumab and docetaxel given together.
Trastuzumab emtansine (Kadcyla®) is trastuzumab with the chemotherapy drug emtansine attached to it. Trastuzumab targets and delivers the chemotherapy to the cancer cells. It may be given after you have already had treatment with trastuzumab, docetaxel or paclitaxel, either separately or together.
You will have trastuzumab emtansine into a vein (intravenously) as a drip (infusion) every 3 weeks.
If the secondary breast cancer does not have receptors for HER2 or for hormones it is called triple negative breast cancer. A drug such as olaparib (Lynparza®) may be used but usually a clinical trial.
Olaparib blocks how PARP proteins work in cancer cells that have a change (mutation) in the BRCA1 or BRCA2 gene. These gene mutations are more common in triple negative breast cancer.
You take olaparib as a tablet twice a day.
Targeted therapy drugs may cause side effects which will depend on the drug you are having. Always tell your cancer doctor or nurse about any side effects you have. There are often ways in which they can be managed.
Effects on the heart
Trastuzumab and pertuzumab may cause changes to the way the heart works. You will have tests to check your heart before and during treatment. If there are any heart problems, your cancer doctor may prescribe drugs to treat these, or stop trastuzumab or pertuzumab for a while.
We have more information about the side effects of trastuzuma and pertuzumab.